android nfc设置切换侦听器
我想在设置首选项时收听nfc启用/禁用,所以我在活动中添加了以下代码android nfc设置切换侦听器,android,toggle,nfc,Android,Toggle,Nfc,我想在设置首选项时收听nfc启用/禁用,所以我在活动中添加了以下代码 IntentFilter filter = new IntentFilter("android.nfc.action.ADAPTER_STATE_CHANGE"); BroadcastReceiver receiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Int
IntentFilter filter = new IntentFilter("android.nfc.action.ADAPTER_STATE_CHANGE");
BroadcastReceiver receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
tv.setText("broadcast received :" + NfcAdapter.getDefaultAdapter(MainActivity.this).isEnabled());
Toast.makeText(MainActivity.this, "broadcast received", Toast.LENGTH_LONG).show();
}
};
registerReceiver(receiver, filter);
但看起来适配器状态改变不起作用
有谁能想到听听nfc的现状吗?请帮忙 此意图的名称是“android.nfc.action.ADAPTER\u STATE\u CHANGE”,而不是“android.nfc.action.ADAPTER\u STATE\u CHANGE”。注意上的D已更改不确定原因,但“android.nfc.action.ADAPTER\u STATE\u CHANGE”与androidManifest配合使用,而不是在活动中进行过滤???您如何在android Manifest中准确使用它?您使用的是特定的类别吗?不,它只是作为一个操作与广播接收器一起工作。为了避免此类错误,请尝试通过引用常量名称。